Spark plug



Jan. 9, 1923.

W. H. CHARD ET AL. SPARK PLUG. FILED SEPT.' 26. 1921.

Patented Jan. 9, 1923. v

UNITED STATES PATENT OFFICE.

WILLIAM H. CHABD, OFKPAICINES, AND WILLIAM F. HILLS, 0F MOUNTAIN VIEW,

CALIFORNIA. i

SPARK PLUG.

Application led September 26, 1921. Serial No. 503,162.

To all who/m, t may concern.'

Be it known that we, WILLIAM H. CHARD and WILLIAM F. HILLS, citizens of Canada and the United States, residing at Paicines and Mountain View, respectively, in the counties of San Benito and Santa Clara and State of California, have invented new and useful Improvements in Spark Plugs, of which the following is a specification.

This invention relates to igniting devices for internal combustion engines especially' those employed in the jump spark plug ignition systems and commonly termed spark plugs.

The principal object ofthis invention` is to provide a spark intensifying device made as a part of the spark plug so as to obtain a stronger and sure spark of the plug at all times.

Before the development of this device spark plugs have been more or less unreliable at times due to the fact that they become foul which generally impaired their proper functioning and often caused them to be totally useless, until they were cleaned and otherwise adjusted. With our inven tion, however, these conditions are taken care of by remedying or rather removing the conditions which cause the trouble.

Other objects and advantages will be apparent during the course of the following description.

In the accompanying drawings forming a part of this specification, and in which like numerals are employed throughout the same,

Fig. l is a vertical section of our spark plug taken on the line 1-1 of Figure 2,

Fig. 2 is a plan view,

Fig. 3 is a detail view in side elevation of the porcelain core of the plug,

Fig. 4t is a view in horizontal section through the head of the plug,

Fig. 5 is a detail view of the grounding clip, and

Fig. 6 is a perspective view of the plug as assembled.

In the accompanying drawings wherein for the purpose of illustration is shown a preferred embodiment of our invention, the numeral 1 represents the metal sleeve having a collar 2 at one end and a threaded opposite end 3 to be received in the spark plug opening of the engine cylinder. The central bore of the sleeve is threaded internally of the collar 2 to receive the threaded metal bushing 4; which in turn is carriedv upon the stem 5 of the porcelain core. The porcelain also has an annular ring 6 which is seated on the shoulder 7 within the sleeve so that the porcelain may be secured in the sleeve by screwing down on the bushing 4 and holding the ring 6 on its seat. The remainder of the length ofthe stem 5 preferably terminated at the lower end of the sleeve as best shown in Figure 1 and with its opposite end made in an enlarged head 8. The top of the head is generally flat and square with a fiber insulating plate 9 of the same shape carried upon the same to insulate the binding posts 10.

In the old style plugs only one central electrode is used and the spark between the sparking end of the same and the ground electrode is never intensified to the desired degree that danger of fouling is reduced to a minimum, therefore with our device we propose to use a plurality of central electrodes preferably five in number and including a relatively large center one 11 with four smaller ones 12 grouped around the center one in squared formation. All of the electrodes extend through channels made to receive them in the porcelain and terminate slightly beyond the lower end of the porcelain stem and with the extreme ends of the four smaller electrodes bent inwardly toward the center one 11. The upper ends of all extend through the head 8 of the porcelain and the plate 9 with the binding posts 10 adapted to secure the Wire leads 13.

In order that the plug may function properly or in other words to ground any selective two of the smaller electrodes we use a clip 14 shaped somewhat like a T so that the head strip 15 thereof may be clamped under the plate 9 in contact with two of the electrodes and with the leg 16 extending down the side of the porcelain head with its end slipped within the metal. bushing 4.

The main lead to the plug is divided at an appropriate place so that two wires 17 and 18 lead to two of the smaller electrodes and when the other two small electrodes are grounded by the clip 14, the spark will jump to the center electrode 11 and then to the two `grounded ones thus obtaining a four way spark or four distinct sparks at one time. rlillewires li' and le may include switches l) and 20 in their` circuit so that iii desired one oit 'the Smaller electrodes may be left dead. insteadv ot leading the two Wires 17 and 1 8 'to two of the Smaller electrodes one of them may be connected tothe center one 1l in fact with this arrangement various dierent combinations may be selected.

A device embodying this principle Will greatlyintensify the `spaziali and inSure firing of the charge under ell conditions,

t is to be `understood that the ilorm oli our invention herewith shown and de* scribed is to 'be taken as a preferred example oi the saine, and'thatwarious changes inthe Shape, Size and arrangement of parte may be resorted. to Without departing from the spirit oiilthe inventionor the ecope'o the subjoined claims.

Having thus described our invention, We clailnzl. A spark plug having la plurality of electrodes arranged in Spaced relation. one ofsaid 'electrodes positioned:concentric to a circle including the other cle'fftrodee, and Spark plug `'gaps between the `concentric electrode and each of theotheraeaidelectrodes being carried bya porcelainwhich in turn is mounted in `a metal sleeve `made ,sev

`'iluiality of' electrodes carried thereliijf, one

of `said electrodes being positioned concentric to a circle including the other electrodes,

means for selectively grounding two o'f the electrodes Wit-n the outliers connected to an ignition system to affect e Spark gap between them and the concentric electrode and between the concentric elect-rode and the grounded ones.

3. In a Spark plug7 an insulated core, a plurality` of electrodes carried thereby, one of Said electrodes being positioned conceir tric to acircle including` the other electrodesn means for selectively grounding two oi the electrodes 'with the others connected to an ignition `eyeten'i to affect a spark gap be tween them and the concentric electrode and between the concentric `electrode und the grounded ones, Said grounding means comprising a clip connecting` two of.' the electrodes With the metal `of the plug.

ln testimony whereof we alin oureigna tures. i

' WILLIAM n. oniinn. WILLIAMl n. HILLS. 

